Positive airway pressure therapy for heart failure

Long-term myocardial effects of noninvasive ventilation in patients with obesity hypoventilation syndrome

INTRODUCTION

Chronic effects of noninvasive ventilation on myocardial function in patients with obesity hypoventilation syndrome (OHS) are scarcely understood. The aim of the present study was to evaluate the long-term effects of volume-targeted bilevel positive airway pressure ventilation (BiPAP) on cardiac parameters and myocardial biomarkers in patients with OHS.

METHODS

Clinically stable patients with OHS referred to the tertiary center for the initiation of long-term BiPAP therapy were consecutively enrolled. At baseline, all participants underwent overnight cardiorespiratory polygraphy. BiPAP therapy using volume-targeted spontaneous/timed mode delivered via an oro-nasal mask was initiated. Beat-to-beat noninvasive monitoring by impedance cardiography was used to assess heart function at baseline and after 3 and 12 months of BiPAP use. Serum troponin 1, N-Terminal Pro-B-Type Natriuretic Peptide (NT-ProBNP), tumor necrosis factor-alpha (TNF-α), and interleukin-6 (IL-6) were monitored.

RESULTS

Thirteen patients (10 men; mean age, 55.8 ± 9.8 years; mean body mass index of 47.8 ± 5.9 kg/m2) were recruited. From baseline to 3, and to 12 months of BiPAP use, left ventricular stroke volume (SV), ejection time (LVET), and ejection time index significantly increased (P = 0.030; P < 0.001; P = 0.003, respectively), while heart rate and systolic time ratio significantly decreased (P = 0.004; P = 0.034, respectively). Reductions in serum NT-proBNP, IL-6 and TNF-α were observed (P = 0.045; P = 0.018; P = 0.003, respectively). No significant changes in serum troponin were detected throughout the study.

CONCLUSIONS

The present findings of increased SV, in association with lengthening of LVET, reductions of NT-proBNP and reductions in circulatory inflammatory markers in patients with stable OHS and chronic moderate-to-severe daytime hypercapnia treated with BiPAP over 1 year support the role of this therapeutic mode in such patients.

Effectiveness of high-flow nasal cannulae compared with noninvasive positive-pressure ventilation in preventing reintubation in patients receiving prolonged mechanical ventilation

Many intensive care unit patients who undergo endotracheal extubation experience extubation failure and require reintubation. Because of the high mortality rate associated with reintubation, postextubation respiratory management is crucial, especially for high-risk populations. We conducted the present study to compare the effectiveness of oxygen therapy administered using high-flow nasal cannulae (HFNC) and noninvasive positive pressure ventilation (NIPPV) in preventing reintubation among patients receiving prolonged mechanical ventilation (PMV). This single-center, prospective, unblinded randomized controlled trial was at the respiratory care center (RCC). Participants were randomized to an HFNC group or an NIPPV group (20 patients in each) and received noninvasive respiratory support (NRS) administered using their assigned method. The primary outcome was reintubation within7 days after extubation. None of the patients in the NIPPV group required reintubation, whereas 5 (25%) of the patients in the HFNC group required reintubation (P = 0.047). The 90-day mortality rates of the NIPPV and HFNC groups (four patients [20%] vs. two patients [10%], respectively) did not differ significantly. No significant differences in length of RCC stay, length of hospital stay, time to liberation from NRS, and ventilator-free days at 28-day were identified. The time to event outcome analysis also revealed that the risk of reintubation in the HFNC group was higher than that in the NIPPV group (P = 0.018). Although HFNC is becoming increasingly common as a form of postextubation NRS, HFNC may not be as effective as NIPPV in preventing reintubation among patients who have been receiving PMV for at least 2 weeks. Additional studies evaluating HFNC as an alternative to NIPPV for patients receiving PMV are warranted.ClinicalTrial.gov ID: NCT04564859; IRB number: 20160901R.Trial registration: ClinicalTrial.gov ( https://clinicaltrials.gov/ct2/show/NCT04564859 ).

Anesthetic Management and Considerations for Electrophysiology Procedures

The number of electrophysiology (EP) procedures being performed has dramatically increased in recent years. This escalation necessitates a full understanding by the general anesthesiologist as to the risks, specific considerations, and comorbidities that accompany these now common procedures. Procedures reviewed in this article include atrial fibrillation and flutter ablation, supraventricular tachycardia ablation, ventricular tachycardia ablation, electrical cardioversion, pacemaker insertion, implantable cardioverter-defibrillator (ICD) insertion, and ICD lead extraction. General anesthetic considerations as well as procedure-specific concerns are discussed. Knowledge of these procedures will add to the anesthesiologist's armamentarium in safely caring for patients in the EP laboratory.

Asian Pacific Society of Cardiology Consensus Statements on the Diagnosis and Management of Obstructive Sleep Apnoea in Patients with Cardiovascular Disease

Obstructive sleep apnoea (OSA) is strongly associated with cardiovascular disease (CVD). However, evidence supporting this association in the Asian population is scarce. Given the differences in the epidemiology of CVD and cardiovascular risk factors, as well as differences in the availability of healthcare resources between Asian and Western countries, an Asian Pacific Society of Cardiology (APSC) working group developed consensus recommendations on the management of OSA in patients with CVD in the Asia-Pacific region. The APSC expert panel reviewed and appraised the available evidence using the Grading of Recommendations Assessment, Development, and Evaluation system. Consensus recommendations were developed and put to an online vote. Consensus was reached when 80% of votes for a given recommendation were in support of ‘agree’ or ‘neutral.’ The resulting statements provide guidance on the assessment and treatment of OSA in patients with CVD in the Asia-Pacific region. The APSC hopes for these recommendations to pave the way for screening, early diagnosis and treatment of OSA in the Asia-Pacific region.

Prevalence, types and treatment of bradycardia in obstructive sleep apnea - A systematic review and meta-analysis

BACKGROUND

The association of obstructive sleep apnea (OSA) with bradycardia is not well-characterized, which may confer significant morbidity and mortality if left untreated. We sought to clarify the prevalence of comorbid OSA and bradycardia, and the effect of continuous positive airway pressure (CPAP) therapy on bradycardia outcomes.

METHODS

We systematically searched four electronic databases (PubMed, Embase, Cochrane Library, Scopus) for randomized or observational studies reporting the co-prevalence of sleep apnea and bradycardia or evaluated the use of CPAP on the incidence of bradycardias. We used random-effects models in all meta-analyses and evaluated heterogeneity using I².

RESULTS

We included 34 articles from 7204 records, comprising 4852 patients. Among patients with OSA, the pooled prevalence of daytime and nocturnal bradycardia were 25% (95% CI: 18.6 to 32.7) and 69.8% (95% CI: 41.7 to 88.2) respectively. Among patients with bradycardia, the pooled prevalence of OSA was 56.8% (95% CI: 21.5 to 86.3). CPAP treatment, compared to those without, did not significantly reduce the risk of daytime (two randomized trials; RR: 0.50; 95% CI: 0.11 to 2.21) or nocturnal bradycardia (one randomized-controlled trial and one cohort study; RR: 0.76; 95% CI: 0.48 to 1.20).

CONCLUSIONS

This meta-analysis demonstrates a high comorbid disease burden between OSA and bradycardia. Future research should explore the treatment effect of CPAP on bradycardia incidence, as compared to placebo.

Prognostic effect of sleep-disordered breathing on hospitalized patients following acute heart failure

BACKGROUND

Identifying patients at risk for poor clinical outcomes following acute heart failure (AHF) is essential. However, data regarding the prognostic effect of sleep-disordered breathing (SDB) and treatment with positive airway pressure (PAP) on clinical outcomes of hospitalized patients following AHF is lacking.

OBJECTIVES

This study investigated the prognostic effect of SDB, PAP treatment, and compliance with PAP treatment on patient clinical outcomes. Polysomnography was performed in hospitalized patients whose left ventricular ejection fraction was < 50%. Patients were divided into groups based on whether SDB was defined as an apnea-hypopnea index ≥ 15 and if they had received PAP treatment. Furthermore, patients with SDB and PAP were subdivided into more and less compliant groups. We assessed the incidences of deaths and rehospitalizations due to heart failure.

RESULTS

Overall, 241 patients were enrolled; 73% had SDB and 29% were initiated on PAP treatment. At a median follow-up of 1.7 years, 74 clinical events (32 deaths, 42 rehospitalizations) occurred. In the multivariable analysis, compared with the non-SDB group, SDB without PAP treatment was associated with an increased risk of clinical outcomes (hazard ratio [HR] 1.79, P = 0.049), whereas SDB with PAP treatment was not (HR 0.78, P = 0.582). Among patients with PAP treatment, a more compliant group was also inversely associated with clinical events (HR 0.11, P = 0.012).

CONCLUSIONS

In hospitalized patients with AHF, untreated SDB was associated with worse clinical outcomes that might be reversible by PAP treatment. However, this potential may be suppressed in less compliant patients.

Reversibility of retinochoroidal vascular alteration in patients with obstructive sleep apnea after continuous positive air pressure and surgical intervention

Purpose

The aim of this work was to study various retinochoroidal parameters in patients with obstructive sleep apnea syndrome (OSAS) and the effect of interventions on these parameters at 6 months follow-up.

Methods

A total of 36 patients were recruited prospectively from the otorhinolaryngology clinics of a large tertiary center between September 2018 to March 2020. The subjects were divided into three groups depending upon intervention chosen for OSAS: Group A (surgery, i.e., uvulopalatopharyngoplasty), group B (medical therapy, i.e., continuous positive air pressure) and group C (no intervention). Various retinochoroidal parameters which were studied included retinal thickness (RT), choroidal thickness (CT), choroidal vascularity index (CVI), arteriovenous ratio (AVR), capillary density index (CDI) in superficial and deep retina, at baseline and 6 months of follow-up after the intervention.

Results

In group A, CT increased significantly at 6 months (332.76 ± 86.41 um) compared to baseline (306.28 ± 78.19) (P = 0.0004). Similarly, CDI at both superficial and deep capillary plexus increased significantly at 6 months (superficial CDI: 0.65 ± 0.04, deep CDI: 0.38 ± 0.01) compared to baseline (superficial CDI: 0.62 ± 0.03, deep CDI: 0.36 ± 0.02) (P = 0.004 and 0.002 respectively). In group B, CT increased significantly at 6 months (361.38 ± 78.63 um) compared to baseline (324.21 ± 76.97 um) (P = 0.008). Also, CVI showed a significant decrease at 6 months (65.74 ± 1.84%) compared to baseline (67.36 ± 1.57%) (P = 0.019). In group C, all except CDI in deep capillary plexus showed a significant decrease at 6 months (0.35 ± 0.01) compared to baseline (0.36 ± 0.02) (P = 0.003).

Conclusion

OSAS alters various retinochoroidal parameters and timely intervention in patients with OSAS can prevent these alterations. Also, these retinochoroidal parameters could serve as one of the markers to monitor the disease progression.

Pathophysiology and Therapeutic Approaches to Acute Decompensated Heart Failure

Acute decompensated heart failure (ADHF) is one of the leading admission diagnoses worldwide, yet it is an entity with incompletely understood pathophysiology and limited therapeutic options. Patients admitted for ADHF have high in-hospital morbidity and mortality, as well as frequent rehospitalizations and subsequent cardiovascular death. This devastating clinical course is partly due to suboptimal medical management of ADHF with persistent congestion upon hospital discharge and inadequate predischarge initiation of life-saving guideline-directed therapies. While new drugs for the treatment of chronic HF continue to be approved, there has been no new therapy approved for ADHF in decades. This review will focus on the current limited understanding of ADHF pathophysiology, possible therapeutic targets, and current limitations in expanding available therapies in light of the unmet need among these high-risk patients.

Consensus on basic conduct during the hospital admission of patients with acute heart failure

Acute heart failure (AHF) is a highly prevalent clinical entity in individuals older than 45years in Spain. AHF is associated with significant morbidity and mortality and is the leading cause of hospitalisation for individuals older than 65years in Spain, a quarter of whom die within 1year of the hospitalisation. In recent years, there has been an upwards trend in hospitalisations for AHF, which increased 76.7% from 2003 to 2013. Readmissions at 30days for AHF have also increased (from 17.6% to 22.1%), at a relative mean rate of 1.36% per year, with the consequent increase in the use of resources and the economic burden for the healthcare system. The aim of this document (developed by the Heart Failure and Atrial Fibrillation Group of the Spanish Society of Internal Medicine) is to guide specialists on the most important aspects of treatment and follow-up for patients with AHF during hospitalisation and the subsequent follow-up. The main recommendations listed in this document are as follows: (1)At admission, perform a comprehensive assessment, considering the patient's standard treatment and comorbidities, given that these determine the disease prognosis to a considerable measure. (2)During the first few hours of hospital care, decongestive treatment is a priority, and a staged diuretic therapeutic approach based on the patient's response is recommended. (3)To manage patients in the stable phase, consider starting and/or adjusting evidence-based drug treatment (e.g., sacubitril/valsartan or angiotensin-converting enzyme inhibitors/angiotensinII receptor blockers, beta blockers and aldosterone antagonists). (4)At hospital discharge, use a checklist to optimise the patient's management and identify the most efficient options for maintaining continuity of care after discharge.

Management of rhythm disorders in Duchenne muscular dystrophy: Is sudden death a cardiac or pulmonary problem?

Dystrophin deficiency results in the cardiomyopathy of variable onset and deficiency. Myocardial scarring commonly results in cardiac dysfunction, with both atrial and ventricular dysrhythmias. Heart failure, rather than arrhythmia burden, remains the strongest cardiac predictor of mortality in this patient population. Current data suggest the overall rate of sudden cardiac death in pediatric dilated cardiomyopathy is significantly lower than in adults. Specifically, in the Duchenne cardiomyopathy population, sudden death from an arrhythmic cause appears to be rare, even in patients with previously diagnosed arrhythmias. Despite this, recommendations for implantable cardioverter-defibrillator (ICD) placement in patients with Duchenne cardiomyopathy has traditionally been extrapolated from adult heart failure recommendations based on decreased left ventricular ejection fraction <35%. Early involvement of the cardiologist in the care for patients with dystrophin-deficient cardiomyopathy is recommended for this reason. The indications for ICD placement to prevent sudden death in patients with Duchenne cardiomyopathy are not well defined. There is little evidence to suggest that placement meaningfully prolongs life in this population, and should be carefully considered in accordance with the care goals of the patient and his family.

Consensus on basic conduct during the hospital admission of patients with acute heart failure

Acute heart failure (AHF) is a highly prevalent clinical entity in individuals older than 45 years in Spain. AHF is associated with significant morbidity and mortality and is the leading cause of hospitalisation for individuals older than 65 years in Spain, a quarter of whom die within 1 year of the hospitalisation. In recent years, there has been an upwards trend in hospitalisations for AHF, which increased 76.7% from 2003 to 2013. Readmissions at 30 days for AHF have also increased (from 17.6% to 22.1%), at a relative mean rate of 1.36% per year, with the consequent increase in the use of resources and the economic burden for the healthcare system. The aim of this document (developed by the Heart Failure and Atrial Fibrillation Group of the Spanish Society of Internal Medicine) is to guide specialists on the most important aspects of treatment and follow-up for patients with AHF during hospitalisation and the subsequent follow-up. The main recommendations listed in this document are as follows: 1) At admission, perform a comprehensive assessment, considering the patient's standard treatment and comorbidities, given that these determine the disease prognosis to a considerable measure. 2) During the first few hours of hospital care, decongestive treatment is a priority, and a staged diuretic therapeutic approach based on the patient's response is recommended. 3) To manage patients in the stable phase, consider starting and/or adjusting evidence-based drug treatment (e.g., sacubitril/valsartan or angiotensin-converting enzyme inhibitors/angiotensin II receptor blockers, beta blockers and aldosterone antagonists). 4) At hospital discharge, use a checklist to optimise the patient's management and identify the most efficient options for maintaining continuity of care after discharge.

High-Flow Nasal Cannula versus Noninvasive Positive Pressure Ventilation in Patients with Heart Failure after Extubation: An Observational Cohort Study

Noninvasive positive pressure ventilation (NPPV) has been widely applied in patients with high-risk extubation failure, including heart failure. High-flow nasal cannula (HFNC) has been demonstrated to benefit patients with heart failure by reducing cardiac preload. This study aimed to compare the effectiveness of HFNC to NPPV for preventing extubation failure in patients with heart failure. This 3-year retrospective and single-center cohort study included patients with heart failure with left ventricular ejection fraction <50% who received prophylactic HFNC or NPPV after scheduled extubation from January 2015 to January 2018 from a medical center with four adult intensive care units. Demographics, comorbidities, diagnosis, and weaning status were collected. The primary outcome was treatment failure within 72 hours after extubation, which was defined as escalation to NPPV or reintubation in the HFNC group and was defined as requiring reintubation in the NPPV group. Secondary outcomes were reintubation within 72 hours, reintubation, duration of stay, and mortality during the intensive care unit and hospital stay. Of the 104 patients analyzed, characteristics of 58 patients in the HFNC group and 46 patients in the NPPV group were compared. The treatment failure within 72 hours in the two groups was not significantly different (25.9% vs 13%, p=0.106). Hypoxemic respiratory failure related treatment failure was significantly higher in the HFNC group. Prophylactic HFNC as first-line therapy had a comparable rate of reintubation within 72 hours to the prophylactic NPPV alone (17.2% vs 13%, p=0.556). Other secondary outcomes were similar between the two groups. Among patients with heart failure, HFNC was not inferior to NPPV for preventing extubation failure and reintubation. However, in case of an impending respiratory failure, selective patients may benefit from rescue NPPV.

Noninvasive Positive Pressure Ventilation for Acute Decompensated Heart Failure

Noninvasive positive pressure ventilation (NIPPV), which can be applied without endotracheal airway or tracheostomy, has been used as the first-line device for patients with acute decompensated heart failure (ADHF) and cardiogenic pulmonary edema. Positive airway pressure (PAP) devices include continuous PAP, bilevel PAP, and adaptive servoventilation. NIPPV can provide favorable physiologic benefits, including improving oxygenation, respiratory mechanics, and pulmonary and systemic hemodynamics. It can also reduce the intubation rate and improve clinical symptoms, resulting in good quality of life and mortality.

Assessment of noninvasive positive pressure ventilation in healthy young volunteers using salivary stress biomarkers

Aim:

We performed a stress assessment of noninvasive positive pressure ventilation (NPPV) using the salivary biomarkers chromogranin A.

Materials & methods:

Twenty healthy volunteers were subjected to NPPV for 30 min. We collected saliva samples before and after NPPV and evaluated chromogranin A.

Results:

We collected saliva samples from 13 volunteers for enzyme measurement. Of the 13 volunteers, 11 showed elevated chromogranin A levels, which were significantly higher after NPPV than before NPPV (p < 0.01). The chromogranin A increase group displayed significantly increased leak flow and reduced respiratory rate and absolute humidity compared with the chromogranin A reduction group.

Conclusion:

The increase of leak volume might be a stress factor in patients receiving NPPV.

Salivary biomarkers are attractive as they are noninvasive and convenient. Noninvasive positive pressure ventilation (NPPV), the delivery of mechanical ventilation to those with respiratory failure, can have complications resulting in stress to the patient. Here, we evaluated stress-related salivary biomarkers during NPPV in healthy individuals. Our results suggest that NPPV might increase stress levels and that humidity and leak volume affected stress.

Sleep Apnea and Heart

Scientific investigations in the past few decades have supported the important role of sleep in various domains of health. Sleep apnea is a highly prevalent yet underdiagnosed sleep disorder representing a valid cardiovascular risk factor, particularly for hypertension. While several studies have demonstrated the benefits of sleep apnea treatment on subclinical cardiovascular measures, there is a paucity of studies proving reduction of cardiovascular events and mortality. Sufficient and high-quality sleep is also important in the maintenance of cardiovascular health. Future investigations should focus on improving identification of patients at greatest risk of adverse cardiovascular s sequalae of sleep apnea and testing the therapeutic benefit of sleep apnea treatment in this vulnerable group.

A mini review of inhaled beta 2 agonists in acute decompensated heart failure requiring respiratory support

Acute decompensated heart failure (HF) results in over one million hospital admissions per year, many requiring invasive or noninvasive mechanical ventilation for respiratory/cardiovascular support. Inhaled beta-2 adrenergic receptor agonists have been shown to be effective at clearance of extravascular lung water in HF patients. However, studies done in the late 1990s and early 2000s, prior to standardization and wide adoption of guideline directed medical therapy for HF, suggested that inhaled beta-2 agonist use increased admissions for HF exacerbations as well as in-hospital mortality. One study even attempted to utilize intravenous Beta-2 agonists in Acute Respiratory Distress Syndrome patients, however the study was stopped prematurely due to an 11% increased mortality in the treatment group. More recently however, studies examining patients who have concurrent diagnoses of chronic obstructive pulmonary disease (COPD) and HF showed that beta-2 agonist therapy resulted in similar or better outcomes compared to controls. Likewise, in-vitro studies, animal models, and studies utilizing chronic heart failure patients treated with nebulized beta-2 agonists with no concurrent respiratory diagnosis had a therapeutic effect of treatment over controls. These studies have the advantage of being performed with the standardization of guideline directed HF medical therapy. In conclusion, while we continue to recommend the use of Beta-2 agonist therapy in patients with concurrent COPD and HF requiring respiratory support, further studies, preferably single or double blinded prospective trials, will need to be performed to determine whether Beta-2 agonist therapy offers morbidity and mortality benefits in patients with strictly acute decompensated heart failure requiring respiratory support.

Troubleshooting Hypoxemia After Placement of an Extraglottic Airway

The case presented here highlights the feasibility of using an extraglottic airway device as a conduit for delivering high levels of lifesaving positive end expiratory pressure (PEEP), as well as other means of combating recalcitrant hypoxia. The case also highlights the merit of an approach to the hypoxic patient with an in-situ extraglottic airway device based not only on deciding if the device is functioning to maintain a patent airway, but also, simultaneously considering the patient's physiology. A 71 year old male suffered an out-of-hospital cardiac arrest. Part of his resuscitation included placement of a dual-balloon extraglottic airway device by EMS. He was hypoxic, but the device seemed to be providing for a patent airway without an air leak. There was also a favorable end-tidal carbon dioxide waveform. The flight team chose to the leave the device in place. PEEP was up-titrated to 17 cmH20 without issue. Sigh breaths, as well as breath holds, were also able to be delivered. The patient's hypoxia improved over the course of the patient's transport, and he ultimately did well.

Evaluation of cardiac function using heart-lung interactions

Heart lung interactions can be used clinically to assist in the evaluation of cardiac function. Application of these interactions and understanding of the physiology underlying them has formed a focus of research over a number of years. The changes in preload induced by changes in intrathoracic pressure (ITP) with the respiratory cycle, have been applied to form dynamic tests of fluid responsiveness. Pulse pressure variation (PPV), stroke volume variation (SVV), end expiratory occlusion test, pleth variability index (PVI) and use of echocardiography are all clinical assessments that can be made at the bedside. However, there are limitations and pitfalls to each that restrict their use to specific situations. The haemodynamic response to treatment with continuous positive airway pressure (CPAP) in left ventricular failure is explained by the presence of heart lung interactions, and works predominately through afterload reduction. Similarly, in other disease states such as acute respiratory distress syndrome (ARDS), the effects of a change in ventilation can provide information about both the cardiac and respiratory system. This review aims to summarise how assessment of cardiac function using heart lung interactions can be performed. It introduces the underlying physiology and some of the clinical applications that are further explored in other articles within the series.

Cardiorespiratory interaction with continuous positive airway pressure

The treatment of choice for obstructive sleep apnoea (OSA) is continuous positive airway pressure therapy (CPAP). Since its introduction in clinical practice, CPAP has been used in various clinical conditions with variable and heterogeneous outcomes. In addition to the well-known effects on the upper airway CPAP impacts on intrathoracic pressures, haemodynamics and blood pressure (BP) control. However, short- and long-term effects of CPAP therapy depend on multiple variables which include symptoms, underlying condition, pressure used, treatment acceptance, compliance and usage. CPAP can alter long-term cardiovascular risk in patients with cardiorespiratory conditions. Furthermore, the effect of CPAP on the awake patient differs from the effect on the patients while asleep, and this might contribute to discomfort and removal of the use interface. The purpose of this review is to highlight the physiological impact of CPAP on the cardiorespiratory system, including short-term benefits and long-term outcomes.

Acute Effects of Positive Airway Pressure on Functional Mitral Regurgitation in Patients with Systolic Heart Failure

Background: Acute effects of positive airway pressure (PAP) [including continuous PAP (CPAP) and adaptive servo-ventilation, an advanced form of bi-level PAP] on functional mitral regurgitation (fMR) in patients with heart failure (HF) with left ventricular (LV) systolic dysfunction remain unclear. Thus, whether PAP therapy reduces fMR in such patients with HF was investigated. Methods and Results: Twenty patients with HF and LV systolic dysfunction defined as LV ejection fraction (LVEF) <50% (14 men; mean LVEF, 35.0 ± 11.5%) with fMR underwent echocardiography during 10-min CPAP (4 and 8 cm H₂O) and adaptive servo-ventilation. For fMR assessment, MR jet area fraction, defined as the ratio of MR jet on color Doppler to the left atrial area, was measured. The forward stroke volume (SV) index (fSVI) was calculated from the time-velocity integral, cross-sectional area of the aortic annulus, and body surface area. fMR significantly reduced on CPAP at 8 cm H₂O (0.30 ± 0.12) and adaptive servo-ventilation (0.29 ± 0.12), compared with the baseline phase (0.37 ± 0.12) and CPAP at 4 cm H₂O (0.34 ± 0.12) (P < 0.001). The fSVI did not change in any of the PAP sessions (P = 0.888). However, significant differences in fSVI responses to PAP were found between sexes (P for interaction, 0.006), with a significant reduction in fSVI in women (P = 0.041) and between patients with baseline fSVI ≥ and < the median value (27.8 ml/m², P for interaction, 0.018), with a significant fSVI reduction in patients with high baseline fSVI (P = 0.028). In addition, significant differences were found in fSVI responses to PAP between patients with LV end-systolic volume (LVESV) index ≥ and < the median value (62.0 ml/m², P for interaction, 0.034), with a significant fSVI increase in patients with a high LVESV index (P = 0.023). Conclusion: In patients with HF, LV systolic dysfunction, and fMR, PAP can alleviate fMR without any overall changes in forward SV. However, MR alleviation due to PAP might be associated with a decrease in forward SV in women with high baseline SV, whereas MR alleviation due to PAP might be accompanied by increased forward SV in patients with a dilated LV.

Acid-base and electrolyte abnormalities in heart failure: pathophysiology and implications

Electrolyte and acid–base abnormalities are a frequent and potentially dangerous complication in subjects with congestive heart failure. This may be due either to the pathophysiological alterations present in the heart failure state leading to neurohumoral activation (stimulation of the renin–angiotensin–aldosterone system, sympathoadrenergic stimulation), or to the adverse events of therapy with diuretics, cardiac glycosides, and ACE inhibitors. Subjects with heart failure may show hyponatremia, magnesium, and potassium deficiencies; the latter two play a pivotal role in the development of cardiac arrhythmias. The early identification of these alterations and the knowledge of the pathophysiological mechanisms are very useful for the management of these patients.

Personalizing mechanical ventilation for acute respiratory distress syndrome

Lung-protective ventilation with low tidal volumes remains the cornerstone for treating patient with acute respiratory distress syndrome (ARDS). Personalizing such an approach to each patient's unique physiology may improve outcomes further. Many factors should be considered when mechanically ventilating a critically ill patient with ARDS. Estimations of transpulmonary pressures as well as individual's hemodynamics and respiratory mechanics should influence PEEP decisions as well as response to therapy (recruitability). This summary will emphasize the potential role of personalized therapy in mechanical ventilation.

Sleep and Heart Failure

Sleep deprivation occurs for many reasons but, when chronic in nature, has many consequences for optimal health and performance. Despite its high prevalence, sleep-disordered breathing is underrecognized and undertreated. This is especially true in the setting of heart failure, where sleep-disordered breathing affects more than 50% of patients. Although the optimal strategy to best identify patients is currently unknown, concerted and consistent efforts to support early recognition, diagnosis, and subsequent treatment should be encouraged. Optimization of guideline-directed medical therapy and concurrent treatment of sleep-disordered breathing are necessary to improve outcomes in this complex high-risk population.